The location of a mobile, wireless or wired device is a useful and sometimes necessary part of many services. A Location Information Server (“LIS”) may be responsible for providing location information to such devices with an access network. The LIS may utilize knowledge of the access network and its physical topology to generate and serve location information to devices.
The LIS, in general terms, is a network node originally defined in the National Emergency Number Association (“NENA”) i2 network architecture addressing a solution for providing E-911 service for users of Voice over Internet Protocol (“VoIP”) telephony. In VoIP networks, the LIS is the node that determines the location of the VoIP terminal. Beyond the NENA architecture and VoIP, the LIS is a service provided by an access network provider to supply location information to users of the network by utilizing knowledge of network topology and employing a range of location determination techniques to locate devices attached to the network. The precise methods used to determine location are generally dependent on the type of access network and the information that can be obtained from the device. For example, in a wired network, such as Ethernet or DSL, a wiremap method is commonplace. In wiremap location determination, the location of a device may be determined by finding which cables are used to send packets to the device. This involves tracing data through aggregation points in the network (e.g., Ethernet switches, DSL access nodes) and finding the port for which packets are sent to the device. This information is combined with data available to the LIS (generally extracted from a database) to determine a final location of the device.
In wireless networks, a range of technologies may be applied for location determination, the most basic of which uses the location of the radio transmitter as an approximation. The Internet Engineering Task Force (“IETF”) and other standards forums have defined various architectures and protocols for acquiring location information from an LIS. In such networks, an LIS may be automatically discovered and location information retrieved using network specific protocols. Location information may be retrieved directly or the LIS may generate temporary uniform resource identifiers (“URI”) utilized to provide location indirectly (i.e., location URI). Geodetic, civic positions and location URIs for a mobile device may be determined as a function of location information from the LIS. A request for geodetic and/or civic locations may provide location information at the time the location request is made. A location URI may generally be passed to another party which can utilize it to retrieve the target device's location at a later time, typically from the same location server that provided the location URI. There is, however, a need in the art to overcome the limitations of the prior art and provide a novel system and method for managing created location contexts in a location server.
One embodiment of the present subject matter provides a method for creating a location URI for determining the location of a target device. The method may comprise receiving a location request for a target device and collecting location context information for the target device including starting information, validating information and policy information. The collected location context information may be encrypted in an LIS and then converted to a form compatible with URI syntax. A location URI may then be constructed as a function of the converted information.
Another embodiment of the present subject matter may provide a method for handling a location request for a target device using a location URI. The method may comprise receiving a location request for a target device from a requesting entity, the target device having a location context information represented by a location URI and including starting information, initial validating information and policy information. The form of the location URI may be verified by an LIS, the form including at least an encrypted context string. The encrypted context string may be extracted and decrypted by the LIS and it may be determined if the location request can continue as a function of the policy information. An estimated location of the target device may then be determined as a function of the starting information and additional validating information collected. This additional validating information may be correlated with the initial validating information, and the estimated location of the target device provided to the requesting entity.
A further embodiment of the present subject matter provides an LIS comprising circuitry for receiving a location request for a target device, circuitry for collecting location context information for the target device including starting information, validating information and policy information. The LIS may also include circuitry for encrypting the collected location context information, and circuitry for converting the encrypted location context information to a form compatible with URI syntax. The LIS may include circuitry for constructing a location URI as a function of the converted information.
One embodiment of the present subject matter provides an LIS comprising circuitry for receiving a location request for a target device, the target device having a location context information represented by a location URI and including starting information, initial validating information and policy information. The LIS may include circuitry for verifying the form of the location URI, the form including at least an encrypted context string, circuitry for extracting and decrypting the encrypted context string, and circuitry for determining if the location request can continue as a function of the policy information. Further, the LIS may include circuitry for determining an estimated location of the target device as a function of the starting information, circuitry for collecting additional validating information, and circuitry for correlating the additional validating information with the initial validating information. The LIS may also include circuitry for providing the estimated location of the target device to the requesting entity.
These embodiments and many other objects and advantages thereof will be readily apparent to one skilled in the art to which the invention pertains from a perusal of the claims, the appended drawings, and the following detailed description of the embodiments.